Maxfield Keck was commissioned to use bas-relief carvings to design artwork for the front of the building, which are clearly visible when viewing the building from the exterior, and represent Transportation (South Tower) and Commerce (North tower).[7]

German American artist Winold Reiss was commissioned to design and create two 22 foot (6.7 m) high by 110 foot (33.5 m) long color mosaicmurals depicting the history of Cincinnati for the rotunda, two murals for the baggage lobby, two murals for the departing and arriving train boards, 16 smaller murals for the train concourse representing local industries and the large world map mural located at the rear of the concourse. Reiss spent roughly two years in the design and creation of the murals. The 16 industry murals chosen for the railroad concourse include:

Fourteen of the murals located in the train concourse were removed in 1972 when the concourse building was demolished, and placed on display at the Cincinnati/Northern Kentucky International Airport at a cost of $1 million.[8] The two Rookwood Pottery murals remained at Union Terminal and have been relocated to the Machine Tool Gallery in the Cincinnati History Museum, while the arriving and departing trains murals were moved in front of the entrance to the Cincinnati Historical Library.[9] With Terminal 1 and Terminal 2 being demolished, nine of the murals are being relocated to the Duke Energy Convention Center.[10] Five murals remain in the main terminal at the airport.

Pierre Bourdelle, son of renowned French sculptor Antoine Bourdelle, also created commissioned artwork for the terminal, including a Jungle-themed mural for the Women's Lounge, men's lounge, baggage checking area, meeting spaces, and the executive offices. All of his artwork, which was all recently restored is available for public view by free tours.[7]

The Union Terminal Company was created to build the terminal, railroad lines in and out, and other related transportation improvements. Construction in 1928 with the regrading of the east flood plain of the Mill Creek to a point nearly level with the surrounding city, a massive effort that required 5.5 million cubic yards of landfill.[4] Other improvements included the construction of grade separatedviaducts over the Mill Creek and the railroad approaches to Union Terminal. The new viaducts the Union Terminal Company created to cross the Mill Creek valley ranged from the well built, like the Western Hills Viaduct,[3] to the more hastily constructed and shabby, like the Waldvogel Viaduct.[11] Construction on the terminal building itself began in 1931, with Cincinnati mayorRussell Wilson laying the mortar for the cornerstone. Construction was finished ahead of schedule,[3] although the terminal welcomed its first trains even earlier on March 19, 1933 when it was forced into emergency operation due to flooding of the Ohio River. The official opening of the station was on March 31, 1933. The total cost of the project was $41.5 million.[citation needed]

During its heyday as a passenger rail facility, Union Terminal had a capacity of 216 trains per day, 108 in and 108 out. Three concentric lanes of traffic were included in the design of the building, underneath the main rotunda of the building: one for taxis, one for buses, and one (although never used) for streetcars. However, the time period in which the terminal was built was one of decline for train travel. By 1939, local newspapers were already describing the station as a white elephant.[3] While it had a brief revival in the 1940s, because of World War II, it declined in use through the 1950s and the 1960s.

In 1971, after the creation of Amtrak, train service at Union Terminal was reduced to just two trains a day, the George Washington and the James Whitcomb Riley. Amtrak abandoned Union Terminal the next year, opening a smaller station elsewhere in Cincinnati on October 29, 1972.[3]

After Amtrak abandoned the station, Southern Railway purchased some of the land to use for its own expanded freight operations in its Gest Street yard. The Southern planned on removing the 450-foot (140 m) long passenger train concourse to allow additional height for its piggyback operations. On May 15, 1973 the Cincinnati City Council's Urban Development and Planning Committee voted 3–1 in favor of designating Union Terminal for preservation as a historic landmark, preventing Southern Railway from destroying the entire building. In 1974, the Southern Railway did tear down most of the train concourse. Before the concourse building was torn down, the fourteen mosaic murals depicting important Cincinnati industries were removed by Besl Transfer Company from the concourse and installed at the Cincinnati/Northern Kentucky International Airport. The only mural which was not preserved was the world map, which was destroyed.

In 1978, Columbus, Ohio real estate development group the Joseph Skilken Organization converted the terminal into a shopping mall known as the "Land of OZ". This was projected to be a family entertainment and shopping complex including a shopping area, roller skating rink, bowling alleys, and restaurants. Skilken invested upwards of $20 million in renovations preparing the terminal in the hope that this would revitalize the complex and help keep people in downtown Cincinnati.

These plans were put into action and on August 4, 1980, after 23 months of conversion construction, the mall had its Grand Opening, with 40 tenants. The complex drew on average 7,900 visitors per day and it would see a high of 54 shops or vendors. The recession of the early 1980s caused the project to fall on hard times. In 1981 the first tenant moved out and by 1982 the number of tenants had fallen to 21. Also in August 1982, the Cincinnati Museum of Health, Science and Industry opened in the terminal. The OZ project officially closed in 1984. However, Loehmann's, a clothing store located in the rotunda remained open until 1985. The passenger drop off ramps that ran under the rotunda were used for a weekend flea market for several years.

The terminal lay empty for the next decade or so. In May 1986 the voters of Hamilton County passed a bond levy to save the terminal from destruction and to transform it into the Cincinnati Museum Center. Former Cincinnati mayor Jerry Springer was one of the major proponents of saving the building and transforming it into a museum. It was opened in 1990 and now provides a home to six organizations:

The renovations also allowed Amtrak to restore service to Union Terminal via the thrice-weekly Cardinal on July 29, 1991. Of the seven Ohio stations served by Amtrak, Cincinnati was the third busiest in FY2010, boarding or disembarking an average of approximately 40 passengers daily.

The Cincinnati Railroad Club occupies "Tower A" above the station, offers public access to the space, and serves as a museum for the former rail yard and station's innovative interlocking system of remote-controlled track switches.

In June 2014 the National Trust for Historic Preservation named Union Terminal as one of the 11 most endangered historic places in the country due to deterioration.[13]

Cincinnatians enjoy the beautiful view

From late 2016 until 2018, most of the museum will be shut down in order to complete much needed structural renovations throughout the entire building, in addition to restoring a number of rooms original to the building. Due to the flat roofs on large portions of the building, water damage has caused rotting to the roofs and walls. The renovation is necessary in order to save the building from collapsing. During the closure, items located in the museum will be stored in The Geier Center, which is the museum's storage facility, and in various traveling exhibits across the country.

The Railroad and the City, A Technological and Urbanistic History of Cincinnati, Written by Carl W. Condit. 1977, Ohio State University Press. ISBN 0-8142-0265-9

Works Progress Administration(ed. Harry Graff)(1943). WPA Guide to Cincinnati: Cincinnati, a guide to the Queen City and its neighbors. Cincinnati: The Cincinnati Historical Society. ISBN 0-911497-04-8.